Continuous-casting mold

ABSTRACT

A continuous-casting mold has an inner mold tube having a plurality of side walls formed with coolant passages and a plurality of profiles extending longitudinally on each of the side walls and each formed with a respective plurality of longitudinally spaced undercut grooves. An outer jacket surrounds the mold tube. Respective connectors each have a base generally complementarily fitting in a respective one of the grooves and a tubular and internally threaded body projecting outward from the respective base. Respective screws engage from outside through the jacket into the bodies.

FIELD OF THE INVENTION

The present invention relates to a mold for the continuous casting of blooms, slabs or billets, with a mold tube surrounded by a jacket and supported by profiles running in the longitudinal direction and distributed over the circumference on the jacket and connected positively to the latter via connectors, cooling passages for the routing of cooling water being distributed over the entire circumference between the jacket and being arranged essentially over the entire mold length.

BACKGROUND OF THE INVENTION

Continuous casting molds are reusable, downwardly open molds for casting metal or alloys. For this purpose, the liquid metal or liquid alloy is conducted through the mold that consists of cooled copper plates and the metal or alloy solidifies in the desired form.

A particular problem with continuous casting is that uniform and careful cooling of the copper tubular mold is advantageous for this purpose. To this effect, coolant is conducted through prefabricated coolant passages, the coolant employed usually being water. In this case, a uniform temperature of the coolant is desirable, so that the mold is not damaged due to sharp local temperature gradients. Furthermore, with a constant cooling capacity, the casting has a higher surface quality.

Continuous casting molds of the type described above are known, for example, from EP 2 014 393 (US 2001/0155570]and from EP 1 468 760 (U.S. Pat. No. 7,422,049). These describe connection profiles as connectors between the mold tube and the jacket, the connection profiles being arranged in the longitudinal direction along the entire circumferential line. In the embodiment according to EP 2 014 393 A1, the connection profile arranged in one piece on the mold tube has a rounded nose, behind which a further nose of a connection strip, connected to the jacket, is engaged. For this purpose, a plurality of fastening screws are provided that reach through the jacket from outside. By contrast, in the embodiment according to EP 1 468 760 B1, there is provision for the profile strips on the mold tube to be designed as T-profile pieces or as dovetail profile pieces, the profile piece on the jacket being shaped correspondingly in order to provide an appropriate connection.

The molds described have the disadvantage, in the first place, that manufacture or machining is relatively complicated, thus increasing the production costs. Moreover, assembly is comparatively complicated, since the respective strips have to be oriented first parallel to one another and then at the correct height, which has proved to be difficult. A particular problem, however, is that a reduced cooling action takes place in the region of the profile strips, thus leading to the sharp local temperature gradients already referred to. This is also intensified in that, in the known solutions, the cooling passages are covered on one side.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide an improved continuous-casting mold.

Another object is the provision of such an improved continuous-casting mold that overcomes the above-given disadvantages, in particular in which as constant and as uniform a cooling capacity as possible is afforded along the entire surface.

SUMMARY OF THE INVENTION

A continuous-casting mold has according to the invention an inner mold tube having a plurality of side walls formed with coolant passages, a plurality of profiles extending longitudinally on each of the side walls and each formed with a respective plurality of longitudinally spaced undercut grooves, an outer jacket surrounding the mold tube, respective connectors each having a base generally complementarily fitting in a respective one of the grooves and a tubular and internally threaded body projecting outward from the respective base, and respective screws engaged from outside through the holes in the bodies.

In other words, according to the invention the rib-shaped supporting profiles arranged on the outer surface of the mold are formed with a plurality of spaced-apart undercut grooves into which engage the connectors that also have a cylindrically tubular body with an internal threaded bore that receives a fastening screw for fixing the jacket. This jacket consists of a plurality of plates that are connected indirectly to the mold tube via screws that engage into the cylindrically tubular body, for which purpose the latter has a corresponding threaded portion. The hollow body is mounted positively inside the recesses on the rib-shaped supporting profiles. The jacket plates can thereby be assembled quickly and in a labor-saving way, since the correct positioning is already defined by only two connection points, and the jacket plate is prevented from being axially displaced longitudinally with respect to the mold tube. The other fastening screws can subsequently be fitted without difficulty.

Furthermore, the cylindrically tubular body with the threaded bore affords a comparatively long threaded portion, so that there is a stable connection. This is not so if the threaded bores were to be threaded directly into the supporting profiles that are designed to be as flat as possible and therefore offer only a small amount of space for a threaded portion.

According to a first advantageous embodiment of the present invention, the grooves with undercuts and the parts engaged therein of the connectors are T-profiles or dovetail profiles. Such profile cross sections can be produced simply, quickly and therefore cost-effectively and, moreover, provide an optimal hold of the connectors.

In order to make positioning even easier when the jacket plates are being assembled, the cylindrically tubular bodies of the connectors each have on an outer end a frustoconical outer surface that serves as a centering aid for the jacket plate to be attached. Furthermore, according to a further embodiment of the invention, each jacket plate has perforations that may preferably be bores into which the cylindrically tubular bodies of the connectors project in the assembled state. Hence, during assembly, the jacket plate first merely has to be positioned roughly, so that the tips of the hollow bodies project into the perforations. When the jacket plate is subsequently being “plugged on”, it is correctly positioned automatically. Alternatively or additionally to this, the perforations could also be designed frustoconically inside the jacket plates.

So that the jacket plate can be connected firmly to the mold tube, the perforations of the jacket plate each have restrictions with a diameter designed for passing the screw shank, but not the screw head. Preferably, in the assembled state, the screw head rests in a countersink of the jacket plate.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is an exploded illustration of a continuous-casting mold with a mold tube and with a jacket,

FIG. 2 is a perspective view of a detail of one side wall of a mold tube,

FIG. 3 is a perspective view of a detail of a supporting profile with connectors,

FIGS. 4 and 5 are diagrammatic views of a connector, and

FIG. 6 is a section through a connection between a jacket plate and supporting profile.

DETAILED DESCRIPTION

According to a first actual embodiment of the present invention, the mold consists of a mold tube 1 and of a jacket 2. The mold tube 1 has supporting profiles 3 distributed over its outer surface and extending in a longitudinal direction 4, so that the mold tube 1 is supported via these in the jacket 2. Furthermore, the side walls of the mold tube 1 are formed with outwardly open cooling grooves or passages 5 that also extend in the longitudinal direction 4 and through which a coolant flows.

FIG. 2 shows a view of a detail of one planar side wall of the mold tube 1 with the supporting profiles 3 and with the coolant passages 5. It can also be seen there and in a view of a detail in FIG. 3 that a plurality of transverse spaced-apart grooves 6 with undercuts 7 are provided at least partially on the is supporting profiles 3. Connectors 8 engage here, each having a cylindrically tubular body 9 with an internal threaded bore 10 that receives a fastening screw (not illustrated in FIGS. 1 to 3). In the embodiment illustrated (FIG. 3), the groove-shaped recess 6 with undercut 7 and the parts 13 of the connector 8 that engage here are T-shaped. However, a dovetail connection or another positive connection could also be provided.

As may be gathered from FIG. 1, a plurality of perforations or holes 12 each centered on a respective axis A and through each of which a fastening screw engages are provided on the jacket 2 that is formed by four planar plates 11 to 11″′. In order to make it easier to push on the jacket plates 11 to 11″′, the cylindrically tubular body 9 is outwardly frustoconically tapered at least at its outer end. Alternatively, the perforation 12 could also be inwardly frustoconically flared at least at its inner end, a positioning aid thus likewise being provided. Moreover, interengaging teeth 17 are formed on the longitudinal edges of the jacket plates 11 to 11″′, so that the jacket plates 11 to 11″′ are connected to one another by dovetailing, thus constituting a specially stable connection.

FIGS. 4 and 5 show front and side views of a single connector 8 with its cylindrically tubular body 9 and T-shaped base part 13.

FIG. 6 shows a diagrammatic illustration of a single connection between a jacket plate 11 and a supporting profile 3. In this case, the cylindrical body 9 fits in the perforation 12 and receives a respective fastening screw 14. The projections prevent the head 15 of the fastening screw 14 from slipping slip through the perforation 12. A multiplicity of such connections affords a stable and easily assembled fastener of the jacket plates 11-11″′ that all together form the jacket 2.

On account of the thermal expansion that the mold tube 1 experiences during continuous casting and of the different expansion between the mold tube 1 and jacket 2, some play between the cylindrically tubular bodies 9 and the corresponding bores 12 in the jacket plate 11-11″′ must be allowed in calculations. 

1. A continuous-casting mold comprising: an inner mold tube having a plurality of side walls formed with coolant passages; a plurality of profiles extending longitudinally on each of the side walls and each formed with a respective plurality of longitudinally spaced undercut grooves; an outer jacket complementarily surrounding the mold tube; respective connectors each having a base generally complementarily fitting in a respective one of the grooves and a tubular and internally threaded body projecting outward from the respective base; and respective screws engaged from outside through the jacket into the bodies.
 2. The continuous-casting mold defined in claim 1, wherein each of the grooves extends transversely of the respective longitudinally extending profile and the passages are defined between the profiles.
 3. The continuous-casting mold defined in claim 1, wherein the bases and the grooves are of T-section.
 4. The continuous-casting mold defined in claim 1, wherein each of the tubular bodies has a frustoconically outwardly tapered outer end.
 5. The continuous-casting mold defined in claim 1, wherein the jacket is formed by a respective side plates juxtaposed with the side walls and each formed with an array of holes aligned with the grooves and through which the screws engage and into which the respective cylindrical bodies engage.
 6. The continuous-casting mold defined in claim 5, wherein each screw has a head and a shank, each of the holes being formed with an internal restriction on which the head of the respective screw bears.
 7. The continuous-casting mold defined in claim 6 wherein each of the holes is countersunk outward of the respective restriction, whereby the screw heads are countersunk beneath an outer face of the respective plate. 